【作者】 刘洋；

【导师】 陈逢军； 叶青山；

【作者基本信息】 湖南大学 ， 机械工程（专业学位）， 2021， 硕士

【摘要】 微结构表面是一种能够实现光学、物理学、生物学等特定功能的微小表面,具有许多优异的性能,如超疏水、自洁、减阻、润滑、耐磨、能量转换等。然而目前报道的对于微结构表面的加工存在毛刺或压痕等缺陷,使微结构表面的功能受到限制,有必要对其进行进一步精密加工以改善其表面质量。目前制备用于微结构表面的合适研磨工具通常具有制备工艺复杂、制备时间长和成本高的缺点。因此本文提出一种基于光热固化技术的微结构磨具制备新方法,并对其光热固化材料、光热固化特性、磨具制备、微结构表面抛光等进行了探讨,主要内容包括以下几点:(1)对光敏树脂金刚石复合材料(Photosensitive resin diamond composites,PRDC)进行了分子动力学模拟。利用MS(Materials Studio)软件对各分子进行了结构建模和几何优化,设计了PRDC的五组质量比。通过分子模拟获得了PRDC的单胞构象、密度、内聚能密度、机械性能以及径向分布函数。(2)研究了PRDC的固化特性与摩擦磨损性能。制备了液态光敏树脂金刚石复合材料,探讨了复合材料质量比、固化深度、固化高度、固化时间对PRDC光固化特性的影响。测试了固化后试样的摩擦磨损性能,得到了其磨损量、摩擦系数与磨痕微观形貌。(3)通过分子模拟和实验研究了热敏树脂金刚石复合材料(Thermosensitive resin diamond composites,TRDC)的固化特性与力学性能。利用MS软件对TRDC进行了质量比的设计和主要性质的预测。制备了液态热敏树脂金刚石复合材料,探讨了复合材料质量比、固化温度、固化时间对TRDC热固化特性的影响。测试了试样的力学性能与摩擦磨损性能,得到了其抗拉强度、显微硬度、磨痕表面微观形貌、磨损量以及摩擦系数。对比了PRDC/TRDC的模拟性能和实验性能。(4)制备了微结构磨具并验证了其抛光性能。光固化下制备的微结构磨具存在翘曲、腔体等现象,热固化下制备的微结构磨具形状完整、尺寸准确、表面形貌较好。基于热固化技术制备出微结构磨具并研究了微结构凹槽与磨具微特征的尺寸。制备磨具的微特征高度收缩率低于4.3%,宽度膨胀率低于6.9%。对铝板和铜板进行了平面抛光,抛光15min后铝板表面存在划痕抛光效果不明显,抛光15min后铜板的表面粗糙度可达到76.667 nm。对微结构表面进行了抛光实验,验证了其抛光可行性,抛光后微槽的底面粗糙度为88.231nm,侧面粗糙度为121.593nm。更多还原

【Abstract】 Micro-structured surface is a kind of surface that can realize the specific functions of optics,physics,biology and so on.It has many excellent properties,such as superhydrophobic,self-cleaning,drag reduction,lubrication,wear resistance,energy conversion.However,there are some defects such as burr or indentation in the processing of micro-structured surface reported at present,which limits the function of micro-structure surface.It is necessary to carry out further precision machining to improve its surface quality.At present,the preparation of suitable grinding tools for micro-structured surface usually has the disadvantages of complex preparation process,long preparation time and high cost.In this paper,a new method of preparation of micro-structured polishing tools based on photo/thermal curing technology was proposed,and its photo/thermal curing materials,photothermal curing characteristics,polishing tool preparation and micro-structured surface polishing were discussed,the main contents are as follows:(1)Molecular dynamics simulation of photosensitive resin diamond composite(PRDC)was carried out.The structure modeling and geometry optimization of each molecule were carried out by using(Materials Studio)MS software,and the mass ratio of photosensitive resin diamond composite was designed.The unit cell conformation,density,cohesive energy density,mechanical properties and radial distribution function of five groups of composites with different mass ratios were obtained by molecular simulation.(2)The curing characteristics and friction and wear properties of PRDC were studied.The liquid photosensitive resin diamond composites were prepared.The effects of mass ratio,curing depth,curing height and curing time on the curing characteristics of the composites were discussed.The friction and wear properties of the cured samples were tested,and the wear amount,friction coefficient and micro morphology of wear marks were obtained.(3)The curing characteristics and mechanical properties of thermosensitive resin diamond composites(TRDC)were studied by molecular simulation and experiments.The mass ratio of TRDC was designed and its main properties were predicted by MS software.The liquid thermosensitive resin diamond composites were prepared.The effects of mass ratio,curing temperature and curing time on the thermal curing characteristics of the TRDC were discussed.The mechanical characteristics,friction and wear properties of the cured samples were tested,and the tensile strength,microhardness,surface morphology,wear amount and friction coefficient were obtained.the simulation and experimental performances of PRDC/TRDC were compared.(4)The micro-structured polishing tool was prepared and its polishing performance was verified.The micro-structured polishing tools prepared under light curing have warping,cavities,etc.,and the micro-structured polishing tools prepared under thermal curing have complete shapes,accurate dimensions,and good surface morphology.The micro-structured polishing tool was prepared based on thermal curing technology,and the size of the microstructure groove and the microfeature of the abrasive tool was studied.The micro-features of the polishing tools with different depth-diameter ratios prepared by thermal-curing have a height shrinkage rate of less than 4.3% and a width expansion rate of less than 6.9% relative to the micro-structured groove.Plane polishing was performed on aluminum and copper plates.After 15 minutes of polishing,the effect of improving the surface quality of the aluminum plates was not obvious.After 15 minutes of polishing,the surface roughness of the copper plates could reach 76.667 nm.A polishing experiment was performed on the microstructure surface to verify the feasibility of polishing.After polishing,the bottom surface roughness of the microgrooves was 88.231 nm,and the side surface roughness was 121.593 nm.更多还原